Lens, light source device, backlight unit, and electronic device

The present disclosure relates to a light diffusion characteristic and a light reflection characteristic, and a light source device, a backlight unit, and an electronic device that include the lens. By causing the light emitted from the light source of the light source device to have both light diffusibility and light directivity using the lens including a lower layer portion having a light diffusion characteristic and an upper layer portion having a light reflection characteristic, it is possible to improve a light emission characteristic of the light source device, and when an optical gap is reduced due to the thickness reduction of the backlight unit, the image quality of the backlight unit can be improved.